Polymet Jena

The nanocrystalline fraction of the natural biopolymer bacterial nanocellulose (BNC) was isolated by controlled degradation resulting in anionic surface modifications. The potential of those nanowhiskers for safe and efficient gene delivery was tested using electrostatic layer assemblies with different poly(ethylene imine)s (2.5 and 25 kDa) and plasmid DNA. For different isolation techniques (sulfuric acid hydrolysis and oxidation) the influence of varying preparation conditions such as concentration of the degrading agent, reaction time and temperature on the physicochemical characteristics of the nanowhiskers like morphology, size, and surface charge could be demonstrated. All nanowhiskers were found to be highly cyto- and hemo-compatible in vitro in short-term (2–8 h) or long-term (24–72 h) studies as well as ex ovo in a shell-less hen’s egg model over 8 h. The use of a polyelectrolyte layer technique based on electrostatic interactions with different poly(ethylene imine)s and plasmid DNA enabled the formation of small sized (ca. 200 nm), DNA stabilizing nanowhiskers and facilitated the transfection of CHO-K1 cells with high biocompatibility. In conclusion, by the use of BNC as sustainable raw material, in combination with optimized and controllable preparation conditions and surface modifications, BNC nanowhiskers modified by a polyelectrolyte layer approach could be used as renewable, “green” drug delivery system for bioactive substances such as nucleic acids.

Objective: Bacterial Cellulose (BC) is an innovative biomaterial with unique properties such as high mechanical strength, high water content and poor degradation in vivo. The fiber network structures show similarities to those of collagen. Recent studies have shown that the BC might have a potential to be used as a scaffold in tissue engineering. Thus, aim of this study was evaluation of the in vivo biocompatibility of BC in the heart and the applicabilities as a patch material for muscular ventricular septal defects (mVSD).

The biomaterial bacterial cellulose (BC) represents an innovative approach for overcoming reconstructive problems associated with extended vascular diseases by providing small caliber vascular grafts (diameter 1.0-3.7, length 5.0-10.0, and wall-thickness 0.7 mm). In a first microsurgical study, the BC implants were attached in an artificial defect of the carotid artery of rats for 1 year. These long term results show the incorporation of the BC under formation of neointima and ingrowth of active fibroblasts. In a second study, the grafts were used to replace the carotid arteries of pigs. After 3 months, these grafts were removed and analyzed both macro- and microscopically. Seven grafts (87.5%) were patent whereas one graft was found occluded. These data indicate that the innovative BC engineering technique results in the production of stable vascular conduits and confirm a highly attractive approach to in vivo tissue engineered blood vessels as part of programs in cardiovascular surgery.